CN114056409A

CN114056409A - Detachable electric propulsion system for rolling bodies-clamping and lifting wheels simultaneously and in combination in longitudinal direction

Info

Publication number: CN114056409A
Application number: CN202110881026.1A
Authority: CN
Inventors: S·范托利; B·莱克恩特
Original assignee: IFP Energies Nouvelles IFPEN
Current assignee: IFP Energies Nouvelles IFPEN
Priority date: 2020-08-04
Filing date: 2021-08-02
Publication date: 2022-02-18
Also published as: US20220040016A1; CA3126475A1; EP3949925B1; FR3113235B1; ES2955441T3; EP3949925A1; AU2021204235A1; JP2022029445A; FR3113235A1; EP3949925C0

Abstract

The invention relates to a removable electric propulsion system (1) for a rolling object, the propulsion system (1) comprising a chassis (2) provided with at least one wheel (3) driven by an electric motor, at least one non-driven wheel (4) and at least one device for coupling the electric propulsion system (1) to the rolling object. The coupling means comprise at least one device providing combined and simultaneous gripping and lifting of at least one wheel of the rolling-object body and the combined and simultaneous gripping and lifting device comprises a frame (23), at least one arm (24) projectable in a longitudinal direction (x) and connected to the frame (23), at least one tilting element (22) and at least one pushing device (20); one of the tilting element (22) and the pushing means (20) is connected to said extendable arm (24) and the other is connected to the chassis (2); said pushing means (20) being able to drive at least one wheel of a roller body into said at least one tilting element (22) along a longitudinal direction (x); the tilting element (22) is tiltable about an axis substantially in a transverse direction (21). The invention also relates to a coupling method and a device for coupling a propulsion system to a rolling object.

Description

Detachable electric propulsion system for rolling bodies-clamping and lifting wheels simultaneously and in combination in longitudinal direction

Technical Field

The present invention relates to the field of transport of rolling bodies, for example rolling beds, such as hospital beds, and more particularly wheelchairs.

The heavy duty movement of rolling can cause difficulties for the user, particularly if such actions are repeated, such as causing musculoskeletal disorders.

Background

In order to make the movement of rolling heavy loads easier and more ergonomic, it has been considered to equip these heavy loads with electric machines. For example, the first idea is to provide each bed with an electric wheel drive system. This solution is expensive because it requires changing or retrofitting all beds, which is not affordable for hospitals. In addition, the drive system and batteries add weight to the bed. Thus, the force required to move the bed is greater when the battery has been depleted.

Similarly, in the field of logistics or trade, it has been envisaged to make all trolleys electrically powered. Also, this solution is expensive.

An alternative is to provide a removable propulsion system for the rolling bodies. Various solutions have been considered.

For example, patent application WO-01/85,086 describes a motorized propulsion system for a bed. The propulsion system is configured to be coupled to one or more points of the bed. Due to the coupling means provided for the propulsion system, the system is not versatile and adaptable to different rolling bodies. In fact, it cannot be coupled to a rolling object that is not provided with a coupling portion. Furthermore, for this propulsion system, all the wheels of the rolling bodies remain in contact with the ground. Thus, the orientation of the coupled assembly (propulsion system and bed) is more complex, the friction is high, and the motorized wheels require more power.

Patent application WO-2012/171,079 describes a second propulsion system for a hospital bed. The propulsion system is configured to lift two wheels of the bed. However, the wheel clamping mechanism is complex and bulky: the transverse dimension (direction parallel to the axis of the motorized wheels) is large (greater than the width of the wheels of the bed) and it may exceed the transverse dimension of the bed, which may not facilitate moving the bed, especially in small spaces, such as hospital corridors or elevators.

Patent application WO-2013/156,030 describes a third propulsion system for a hospital bed. The propulsion system is configured to lift two wheels of the bed. However, the lift system requires multiple actuators. It is therefore complicated.

French patent application FR-3,089,786 filed by the applicant is also known. This solution allows to lift the wheels of the rolling bodies in a transversal direction when they are at an angle of 90 deg., thus providing the coupling of the rolling bed to the electric propulsion system. However, this system is not suitable for rolling bodies provided with non-oriented wheels, such as the rear wheels of wheelchairs.

In order to be able to grip and lift the wheels of a rolling body in a simple and fast manner, the invention relates to a detachable electric propulsion system for a rolling body with orientable wheels and non-orientable wheels. The propulsion system comprises a chassis provided with at least one wheel driven by a motor. The propulsion system further comprises at least one non-driven wheel, preferably two non-driven wheels, and at least one coupling device for coupling the electric propulsion system to the rolling bodies. Furthermore, the coupling means comprise at least one device for gripping and lifting in combination and simultaneously at least one wheel of a rolling object, and the device for gripping and lifting in combination and simultaneously comprises a frame, at least one arm which can be extended in a longitudinal direction and is connected to the frame, at least one tilting element and at least one pushing device; one of the tilting element and the pushing means is connected to said extendable arm and the other is connected to the frame; the pushing means are capable of driving at least one wheel of the animal body in the longitudinal direction into the at least one tilting element; the tilting element can be tilted about an axis of the substantially transverse direction, orthogonal to the longitudinal direction in the horizontal plane.

Thus, once coupled, the wheels of the rolling bodies correspond in the longitudinal direction to the main direction of displacement of the electric propulsion system.

Disclosure of Invention

The invention relates to a removable electric propulsion system for a rolling object, said propulsion system being provided with a chassis of at least one wheel driven by an electric motor, at least one non-driven wheel and at least one coupling device for coupling the propulsion system to the rolling object. Furthermore, the coupling means comprise at least one means for gripping and lifting in combination and simultaneously at least one wheel of the rolling bodies. Furthermore, the combined and simultaneous gripping and lifting device comprises a frame, at least one arm extendable in a longitudinal direction and connected to the frame, at least one tilting element and at least one pushing device; one of the tilting element and the pushing means is connected to said extendable arm and the other is connected to the frame; said pushing means being capable of driving at least one wheel of a roller body into said at least one tilting element along said longitudinal direction; the tilting element is tiltable about an axis in a substantially transverse direction.

Preferably, the extendable arm supports at least one of the at least one non-drive wheels.

According to a variant of the invention, said means for combined and simultaneous gripping and lifting comprise at least one means for limiting the angular clearance of at least one tilting element.

Advantageously, an access stop is positioned on said frame or on said tilting element.

According to an embodiment of the invention, said pushing means comprises at least one transversal axis roller secured to said extendable arm or to said frame.

Preferably, the pushing means comprises a first transverse axis roller and a second transverse axis roller fastened to the extendable arm or the frame, the first roller being configured to contact the wheel of the rolling object before the second roller, the first roller having an axis of lower height than the second roller.

Preferably, the diameter of the first roller is smaller than the diameter of the second roller.

According to one configuration of the invention, the coupling device is adjustable along the chassis in the longitudinal direction.

Advantageously, the pushing means comprise two guides extending substantially in the longitudinal direction, said guides being configured to prevent pivoting of the wheels of the rolling bodies.

According to one embodiment of the invention at least one tilting element comprises means for adjusting the width of the tilting element, preferably a mobile flange or a spacer.

Preferably, the electric propulsion system comprises two combined and simultaneous gripping and lifting devices, each dedicated to the wheel(s) of the rolling bodies, the two combined and simultaneous gripping and lifting devices moving in transverse translation with respect to each other.

According to an embodiment of the invention, the frame is connected to the chassis by a sliding connection in a transverse direction, preferably by an actuator.

According to one variant of the invention, a device lift is clamped and lifted in combination and simultaneously, the lift being configured to ensure that the ground clearance in the raised position is greater than a predetermined height, preferably between 30mm and 50mm, more preferably close to 40 mm.

Preferably, the raising means comprise at least one return spring and/or at least one counterweight and/or at least one driven rod.

Advantageously, a (second) stop is positioned on said frame or said extendable arm to provide contact of the tilting element in the raised position.

The invention also relates to a coupled assembly of a rolling body, preferably comprising at least one non-oriented wheel, and an electric propulsion system according to one of the above, said rolling body being coupled to said electric propulsion system by said coupling means.

Furthermore, the invention relates to a method for coupling a rolling object to an electric propulsion system as described above, comprising the following steps.

a) Moving the electric propulsion system so that it is close to at least one wheel of the rolling bodies,

b) extending the extendable arm, thereby enabling the at least one wheel of the rolling-object body to be positioned between the tilting element and the pushing means,

c) moving the electric propulsion system so that the at least one wheel of the rolling bodies is positioned between the tilting element and the pushing means,

d) shortening the extendable arm so that the pushing means or the tilting element contacts the at least one wheel of the rolling bodies,

e) continuing to shorten the extendable arm, thereby causing the pushing means to drive the at least one wheel of the animal body into the tilting element.

Preferably, the electric propulsion system comprises two devices that are gripped and lifted in combination and simultaneously, and the method comprises at least the following steps:

a) moving the electric propulsion system, so that it is close to the two wheels of the rolling bodies,

b) at least one of the two combined and simultaneously gripping and lifting means is moved laterally with respect to the other combined and simultaneously gripping and lifting means,

c) extending the extendable arm of each combined and simultaneously gripping and lifting device, so that the space between the tilting element and the pushing means allows the passage of the wheel of the rolling body,

d) moving laterally at least one of the two combined and simultaneously gripping and lifting means with respect to the other combined and simultaneously gripping and lifting means, opposite to the direction of step b), until each wheel of the rolling bodies is positioned between the pushing means and the tilting element,

e) the extendable arm is shortened so that each wheel of the rolling bodies is driven into each tilting element by means of the pushing means.

Drawings

Further characteristics and advantages of the system and method of the invention will become apparent from reading the following description of various embodiments, given by way of non-limiting example, with reference to the accompanying drawings, in which:

figure 1 is a top view of an electric propulsion system according to a first embodiment of the invention,

figure 2 is a top view of an electric propulsion system according to a second embodiment of the invention,

figure 3 is a side view of an electric propulsion system according to a first variant embodiment of the invention,

figure 4 is a side view of an electric propulsion system according to a second variant embodiment of the invention,

figure 5 is a top view of the propulsion system according to the invention coupled to a rolling object,

figure 6 shows the various steps of realising a first variant of the combined and simultaneous gripping and lifting device according to the invention for gripping and lifting the wheel of a rolling object,

figure 7 shows the various steps of realising a second variant of the combined and simultaneous gripping and lifting device according to the invention for gripping and lifting the wheel of a rolling object,

figure 8 shows the various steps of realising a third variant of the combined and simultaneous gripping and lifting device according to the invention for gripping and lifting the wheel of a rolling object,

figure 9a shows a first step of a method for gripping and lifting a wheel of a rolling object from the propulsion system of the invention,

figure 9b shows a second step of the method for gripping and lifting a wheel of a rolling object from the propulsion system of the invention,

figure 9c shows a third step of the method for gripping and lifting a wheel of a rolling object from the propulsion system of the invention,

figure 9d shows a fourth step of the method for gripping and lifting a wheel of a rolling object from the propulsion system of the invention,

figure 9e shows a fifth step of the method for gripping and lifting a wheel of a rolling object from the propulsion system of the invention,

figure 9f shows a sixth step of the method for gripping and lifting a wheel of a rolling object from the propulsion system of the invention,

figure 9g shows a seventh step of the method for gripping and lifting a wheel of a rolling object from the propulsion system of the invention,

figure 10 shows another embodiment of the propulsion system of the present invention,

figure 11a shows the configuration of an embodiment of the combined and simultaneous gripping and lifting device of the propulsion system of the invention, with the raising device in the rest position,

figure 11b shows the configuration of an embodiment of the combined and simultaneously gripping and lifting device of the propulsion system of the present invention, wherein the lifting device in the rest position is shown in dashed lines and in the raised position in solid lines,

figure 12 shows, for a first embodiment of the system comprising a single tilter, the force applied to the combined and simultaneously gripping and lifting device and the height of the wheels of the rolling bodies according to the applied displacement, and

figure 13 shows the force applied to the combined and simultaneously gripping and lifting device and the height of the wheels of the rolling bodies according to the applied displacement, for a second embodiment of the system comprising a filter and an angular gap limiting device.

Detailed Description

The invention relates to a detachable electric propulsion system for rolling bodies. An electric propulsion system is understood to be a detachable system for assisting the movement of the rolling bodies, thereby limiting the force required for the displacement of the rolling bodies. The electric propulsion system comprises at least one electric motor for driving it. A rolling object is an object that includes at least two wheels to move it.

The rolling bodies may have any shape, which may in particular be rolling beds, in particular such as those used in hospitals; a wheelchair; carts, such as, for example, those used for logistics, hospital logistics, or commercial logistics (e.g., shopping carts); such as any roll furniture. Such a rolling body comprises at least two wheels, preferably three or four wheels. According to a variant of the invention, at least one wheel, preferably both wheels, of the rolling body are idle wheels (or orientable wheels), i.e. eccentric wheels orientable about a vertical axis. The rolling bodies are preferably non-motorized.

The electric propulsion system of the invention is particularly suitable for rolling bodies with non-oriented wheels, such as wheelchair rear wheels. These non-oriented wheels are advantageously those that are gripped and lifted in the electric propulsion system of the invention.

The electric propulsion system according to the invention comprises:

the chassis is provided with at least one motorized wheel, i.e. a wheel driven by an electric motor;

at least one non-motorized wheel, i.e. a wheel not driven by an electric motor. The non-motorized wheel may be connected to the chassis, in particular, by means of an arm that is extendable in the longitudinal direction. Preferably, the system comprises at least two non-motorized wheels,

-at least one means for coupling the propulsion system to the rolling bodies, the coupling means comprising at least one means for combining and simultaneously gripping and lifting at least one wheel of the rolling bodies. In other words, the combined and simultaneous gripping and lifting device is configured to grip (grip) and lift at least one wheel of the rolling bodies simultaneously. A combined and simultaneous gripping and lifting device is understood to be a device that allows to grip and lift at least one wheel of a rolling object simultaneously by the combined action of a single actuator. The combined and simultaneous gripping and lifting device therefore comprises a single control member which simultaneously allows gripping and lifting of at least one wheel of the rolling body. In other words, such combined and simultaneously gripping and lifting device differs in that

One aspect is different from a gripping and lifting device with two different controls: one for gripping and the other for lifting; these devices do not allow combined action to be achieved by a single common control,

another aspect is the continuous gripping and lifting action provided from the means of gripping and lifting, even instantaneously.

The use of combined and simultaneous clamping and lifting means is particularly advantageous. In fact, the kinematics of coupling the rolling bodies with the propulsion system are simplified by means of a combined gripping and lifting action. Moreover, this simplification related to the synchronization of the gripping and lifting actions enables the coupling to be achieved more quickly, even partially, than when these actions are separated.

This combined and simultaneous gripping and lifting device thus makes it possible to couple any rolling bodies (since no coupling means are required on the rolling bodies) to the propulsion system simply and quickly. Furthermore, such a propulsion system allows for gripping and lifting both orientable wheels and non-orientable wheels of the rolling bodies.

According to the invention, the combined and simultaneously clamping and lifting device comprises a frame, at least one arm which is extendable in the longitudinal direction and connected to the frame, at least one tilting element and at least one pushing device. One of the tilting element and the pushing means is connected to said extendable arm and the other is connected to the frame. For example, the tilting element may be connected to the frame (e.g., pivotally connected by a transverse axis), while the pushing device may be connected (e.g., fastened) to the extendable arm. Alternatively, the tilting element may be connected to the extendable arm (e.g. pivotally connected by a transverse axis) and the pushing means may be connected (e.g. fastened) to the frame.

The pushing device is capable of driving at least one wheel of the animal body in the longitudinal direction into the tilting element. When the pushing means is positioned on the extendable arm, the longitudinal movement of the extendable arm drives the wheel towards the tilting element and then into the tilting element. When the pushing means is positioned on the frame, the longitudinal movement of the extendable arm is transferred to the tilting element. In this case, the pushing means serve to prevent the wheel from continuing its longitudinal movement. The pushing device (the force exerted on the pushing device by the wheels of the rolling bodies) thus drives the wheels into the tilting element. Thus, the tilting element and the pushing device face each other in the longitudinal direction.

Furthermore, the tilting element can be tilted about an axis of the substantially transverse direction.

The wheels of the rolling bodies can thus be pushed into the tilting element by means of the pushing means by a movement of the extendable arm in the longitudinal direction and directed towards the frame. Furthermore, the continuation of the longitudinal movement of the extendable arm, seen from the contact of the wheel with the tilting element, enables the gripping and lifting of the wheel of the rolling object in the tilting element. The tilting element is designed to tilt automatically under the action of the force of the wheel of the rolling body and its displacement in the longitudinal direction. Thus, the tilting element has no tilt control means.

Furthermore, the tilting element is connected to the frame or the extendable arm by a pivotal connection in a substantially transverse direction. Thus, the tilting element can tilt about this transverse axis when the wheel of the rolling object moves in the longitudinal direction.

The tilting element may in particular be a tilter. The recliner according to the invention comprises a two-piece curved part which is pivotably connected about an axis, preferably a transverse axis, about which the curved part can be tilted. The two pieces of the curved member are joined substantially at a transverse axis that acts as a pivot. In other words, the bend of the recliner is located at the transverse axis. The wheel of the rolling object is first brought into contact with one of the two pieces at a first contact point, it is tilted around the first contact point and then brought into contact with a second contact point on the other part of the tilter. Longitudinal displacement of the wheels driven by the pushing means moves the centre of gravity of the assembly relative to the transverse pivot axis and causes the assembly to tilt about that pivot axis.

The frame is connected to the chassis by a fixing means or a sliding connection. Fastening to the chassis may be particularly employed when it is desired to grip a single wheel of a rolling body (e.g., a tricycle). The sliding connection provides an improved degree of system compliance, allowing the two wheels of the rolling body to be clamped.

For example, the motorized wheel may be provided at one longitudinal end of the chassis, while the two non-motorized wheels may be provided at the other longitudinal end of the propulsion system, on the extendable arm, the vertical axis of the motorized wheel being preferably on the median perpendicular to the vertical axis of the non-motorized wheel in plan view. Thus, the perpendicular bisector of the vertical axis extends in the longitudinal direction of the chassis (and the propulsion system).

The non-driven wheel of the propulsion system and/or the non-driven wheel of the rolling body may comprise an orientable eccentric.

An orientable eccentric is understood to be an eccentric idler wheel orientable about a vertical axis. In other words, the wheels may pivot about a vertically oriented axis relative to the undercarriage, and the orientation axis of the wheels is eccentric (non-uniform) relative to the vertically oriented axis. Thus, motion imparted to the chassis tends to orient the wheels in a direction opposite to the motion-induced displacement imparted to the chassis. Thus, the wheel orients itself automatically, thereby facilitating maneuverability of the system.

A non-oriented wheel is understood to be a wheel which cannot pivot relative to the chassis or the rolling bodies themselves.

Preferably, the electric propulsion system may comprise handlebars enabling handling, displacement and orientation of the electric propulsion system by a user.

The coupling of the rolling bodies to the propulsion system is achieved by at least one wheel of the rolling bodies, which may be an idler wheel (e.g. orientable by the eccentric effect of the vertical axis) or may be a non-oriented wheel of the rolling bodies. Thus, the rolling bodies do not need to be adapted to the electric propulsion system, which makes the electric propulsion system universal for various rolling bodies. Preferably, the coupling of the rolling bodies to the propulsion system can be achieved by two wheels of the rolling bodies, which simplifies the coupling method and the associated coupling means.

In the present description, the terms "longitudinal", "transverse", "horizontal" and "vertical" determine the axis and/or direction when the system is standing on a flat and horizontal ground (i.e. a ground that is not inclined, in other words, without height differences on the ground) and in the operating position.

The longitudinal direction corresponds to the main displacement direction of the electric propulsion system, i.e. the direction in which the energy required for the displacement of the system is minimized.

The transverse direction (also referred to as "transverse direction" in the rest of the description) is a direction orthogonal to the longitudinal direction of the system in the horizontal plane.

The vertical direction is orthogonal to the horizontal plane of the system.

According to a preferred embodiment of the invention, the extendable arm may support at least one non-driven wheel. The position of the non-driven wheels on the extendable arms enables participation in bearing weight when the rolling objects are coupled to the propulsion system. Furthermore, the non-driven wheel may thus be positioned at one longitudinal end of the propulsion system, which makes it possible to improve the manoeuvrability and limit the number of wheels required by the system.

Preferably, the means for combined and simultaneous gripping and lifting may comprise at least one means for limiting the angular clearance of at least one tilting element. The angular gap limiting device may in particular limit the angular gap of the at least one tilting element. Thus, the force required to initiate wheel gripping and lifting of the roll-fed body can be reduced. In a sense, the angular play limiting device functions in a manner similar to the addition of a tilting element in the system. Thus, the angular gap limiting device facilitates gripping and preliminary lifting of the wheel of the rolled object. The angular gap limiting means also enable to position the lowest point of the tilting element with respect to the ground and thus to define the height of the contact between the tilting element and the wheel of the rolling body.

According to an advantageous embodiment of the invention, an approach stop can be positioned on the frame or on the tilting element. It may advantageously be fastened to the frame or the tilting element. The proximity stop may in particular comprise a portion in the longitudinal direction that stands in the direction of the pushing device. The purpose of this proximity stop is to enable contact between the wheels of the rolling bodies and the combined and simultaneously clamped and lifted device. This also achieves that the combined and simultaneously clamped and lifted device is prevented from lateral displacement when it can move laterally. Such a proximity stop also allows the system to dampen the impact caused by the contact. It may comprise a component made of rubber or an impact bumper material (e.g., an elastomer).

The contact between the proximity stop and the wheel of the rolling body enables an improved positioning of the wheel, facilitating the gripping and lifting of the wheel in the electric propulsion system.

Advantageously, the pushing means may comprise at least one transversal axis roller fastened to a support connected to the extendible arm or to the frame. For example, the support may be secured to the extendable arms or to the frame. Alternatively, the support may be connected to the extendable arms or to the frame by a sliding connection in the transverse direction. The roller wheel is thus substantially in the transverse direction, which enables the wheel of the rolling object to be driven in the longitudinal direction. The roller is used to provide contact between the pushing device and the wheel. The pushing device with at least one roller achieves an improvement in the service life of the system. Positioning the roller on the extendable arm enables the roller body's wheel to be driven in the direction of the tilting element by longitudinal displacement of the extendable arm. Furthermore, the roller wheel serves to generate a lifting movement by means of the tilting element when the rolling bodies have come into contact with the tilting element.

According to a preferred variant of the invention, the pushing means can comprise a first transverse-axis roller and a second transverse-axis roller fastened to a support connected to the extendible arm or to the frame. In other words, the two rollers are parallel to each other. Further, the first roller may be configured to contact a wheel of the rolling object before the second roller. In other words, the distance between the tilting element and the first roller is shorter than the distance between the tilting element and the second roller. Further, the height of the axis of the first roller may be lower than the height of the axis of the second roller. The first roller wheel is therefore used in particular to initiate the thrust exerted on the wheel of the rolling bodies (inducing a thrust exerted on the wheel of the rolling bodies) until it comes into contact with the tilting element, itself driven by the extendable arm, or until the longitudinal displacement of the wheel driven by the tilting element is stopped. Therefore, the first roller preferably is not positioned too high. Then, as the wheel of the rolling object is gradually lifted, the wheel is gradually brought into contact with the second roller. The positioning of this second roller constitutes an obstacle to the retention of the wheel of the rolling body in the tilting element.

According to an advantageous variant of the invention, the diameter of the first roller can be smaller than the diameter of the second roller. Thus, the first roller has a reduced diameter, which can come into contact with the second roller once the wheel starts to lift. Furthermore, since the second roller wheel has a larger diameter, it constitutes a better obstacle for retaining the wheel of the rolling bodies in the tilting element.

The embodiment with double rollers provides a great adaptability of the system to the diameters of the wheels of various rolling bodies.

According to one configuration of the invention, the coupling device is adjustable in the longitudinal direction along the chassis. In other words, the coupling device may be moved longitudinally along the chassis, thereby further improving the adaptability of the coupling device to various rolling bodies. Thus, the coupling device may be connected to the chassis by a sliding connection having a longitudinal axis. The longitudinal displacement of the coupling device may be effected manually, and once the displacement is completed, this position may be maintained by means of pins, which may be provided in various longitudinally distributed apertures, for example. Such longitudinal displacement may alternatively be provided by an actuator such as a hydraulic, pneumatic or electric cylinder. The longitudinal adjustment may in particular enable an improved compactness of the assembly and/or an improved joint stability, for example for wheelchairs comprising a storage compartment at the rear.

Advantageously, the pushing means may comprise at least two guides extending substantially in the longitudinal direction. For example, the two guides can be positioned on both sides of the roller, the two guides being oriented in the direction of the tilting element. The two guides may be configured as: when the pushing means is moved towards the tilting element, the wheel of the rolling body is prevented from pivoting when it can be oriented. The system thus facilitates gripping and lifting an orientable wheel of a rolling object in an inclined element.

According to a variant of the invention, at least one tilting element may comprise means for adjusting the width of the tilting element. The width of the tilting element can thus be adapted to the width of the wheel of the rolling body. The tilting element with the width adjustment device enables adaptation to both simple wheels and double wheels. A simple wheel consists of a single wheel that rotates about a single horizontal axis of rotation. The double wheel consists of two wheels rotating around a single horizontal rotation axis. The means of adjusting the width of the tilting elements allow to limit the gap between the wheels of the rolling bodies and the tilting elements, allowing to improve the grip and the lifting of the wheels of the rolling bodies, in particular when they are orientable, and to improve the fixing of them.

The width of the tilting element is understood to be the distance between the ends of the tilting element, which ends extend along the axis of rotation of the tilting element. For example, when the axis of the tilting element is substantially transverse, the width of the tilting element is understood to be the distance between the ends of the tilting element in the transverse direction. The width of the tilting element can thus be adapted to the width of the wheel, which can be a simple wheel or a double wheel.

Alternatively, in the case of non-directional wheels, the tilter may be provided with sufficient width to accommodate both simple and dual wheels. In other words, the width of the tilter is greater than the maximum width of a simple wheel and/or a double wheel of a rolling-object body intended to be coupled to the electric propulsion system.

Preferably, the means for adjusting the width of the tilting element may be a moving flange. The moving flange is for example a part, a plate or a plate, which can be moved in translation in the direction of the axis of the tilting element. Thus, the user can position the flange to have a width suitable for the wheel of the rolling body.

According to another variant, the means of adjusting the width of the tilting element may be a mobile shim. Thus, the spacer can be placed on or removed from the tilting element. Groups of shims may be used to accommodate various wheel widths of the rolling bodies. The spacer may be removable.

According to a preferred embodiment of the invention, the coupling device may be configured to simultaneously effect clamping and lifting of at least two wheels of the roll-reduced body. Thus, the system may comprise two combined and simultaneous gripping and lifting devices, each configured to grip and lift a different wheel of the rolling bodies. Furthermore, the two combined and simultaneously gripping and lifting devices may be moved in a lateral translation with respect to each other. It is thus possible to position the tilting element and the pushing means so that each of the two wheels of the gripped rolling bodies is between the tilting element and the pushing means.

The two extendable arms of each combined and simultaneously gripping and lifting device may then be actuated by a single controller. In other words, a common controller controls both actuators, e.g. cylinders, simultaneously, so that each extendable arm can be extended or shortened simultaneously.

Alternatively, the system may comprise combined and simultaneous gripping and lifting means, allowing gripping and lifting of the two wheels of the rolling body. For example, two pushing means may then be connected to a single extendable arm, at least one pushing means being connected to the extendable arm by a sliding connection in the transverse direction, to achieve relative spacing or movement of the two means together in the transverse direction. Similarly, at least one of the two tilting elements is connected to the frame by sliding, so as to enable the positioning of the two tilting elements with respect to the wheel of the rolling body to be gripped.

According to one configuration of the invention, the frame can be connected to the chassis by means of a sliding connection in the transverse direction, for example an actuator such as a hydraulic, electric or pneumatic cylinder. This configuration is particularly advantageous when two wheels of the rolling bodies are to be gripped and lifted simultaneously. In fact, the lateral sliding connection allows to move the tilting element and the pushing means apart or together by means of the lateral sliding connection, positioning them so that the wheels of the rolling bodies are between the tilting element and the pushing means, thus facilitating the simultaneous and combined operation of gripping and lifting the wheels of the rolling bodies. For example, the frames may be moved apart by a lateral sliding connection. The advancing system is then moved forward and/or the extendable arms are pushed aside to move each pushing device away from the facing tilting element, so that each of the two wheels of the rolling bodies is positioned between the pushing device and the tilting element of the combined and simultaneously gripping and lifting device. The two frames are then approached to each other by means of a transversal sliding connection, so as to position each of the two wheels to be gripped of the rolling bodies between the tilting element and the opposite pushing means.

Preferably, the combined and simultaneous gripping and lifting means may comprise a lifting means configured to ensure that the ground clearance in the lifted position is greater than a predetermined height. In fact, in the rest position of the combined and simultaneously gripping and lifting device (which is defined by the position of the combined and simultaneously gripping and lifting device), which does not have any movement and therefore does not support any wheels, at least a portion of the gripping element (for example, the tilting element) can be close to the ground to facilitate gripping and lifting the wheels of the rolling-object body. This position is therefore advantageous for facilitating the coupling, but is particularly inconvenient when it is desired to handle the propulsion system without coupling to a rolling object, for example when the user is using the propulsion system in scooter mode, the user standing on a platform supported by the chassis, since the ground clearance is then very limited. Thus, in the rest position, the propulsion system may jam or stop often as soon as a small obstacle occurs. Furthermore, such a low ground clearance may lead to damage to the combined and simultaneously clamping and lifting device. This is why a step-up device can be provided. The raising means allows to raise (raise) the gripping element (e.g. the tilting element) without the need to grip and lift the wheels of the rolling bodies to increase the ground clearance. For example, a ground clearance of about 40mm may maintain a compact and easy to use system and limit the risk of blockage and damage to the system. Such a step-up device is also advantageous for use of the propulsion system in scooter mode, thereby preventing the user from falling.

Preferably, the predetermined height may range between 30mm and 50mm, preferably around 40mm, to provide sufficient ground clearance.

Advantageously, the raising means may comprise at least one return spring and/or at least one counterweight and/or at least one driven rod.

The return spring may return the tilting element to the raised position, for example, once the system is not coupled to the rolling object. The return to the raised position is automatic.

A counterweight positioned on the tilting element, for example on the side opposite to the side near the ground in the rest position (without counterweight), may naturally bring the rest position back to the position near the raised position.

A rod driven by a cylinder, a linear actuator driven by a motor, or any other drive system may also move the clamping element upward, increasing the ground clearance.

According to another variant, the extendable arms can be used to move the tilting element closer to the pushing means (or vice versa to move the pushing means closer to the tilting element). When the longitudinal displacement approaches the end sound, the pushing means and the tilting element are in contact, which causes the tilting element to rise. The intermediate part provided on the pushing means or the tilting element may facilitate the contact and the lifting of the tilting element.

Advantageously, a stop may be positioned on the frame or the extendable arm to provide contact of the tilting element in the raised position. The stopper may be made of rubber or an equivalent shock absorber material. The purpose of the stop is to keep the tilting element in the raised position.

The invention also relates to a coupled assembly of a rolling object body and an electric propulsion system as described above, the rolling object body being coupled to the electric propulsion system by means of a coupling device. Such coupled assembly facilitates handling of the rolling bodies, particularly in small spaces, as well as coupling and uncoupling operations.

The coupling assembly is particularly suitable for use with rolling stock having at least one non-directional wheel, preferably two non-directional wheels, such as wheelchairs whose rear wheels are non-directional. In fact, the propulsion system easily grips and lifts at least one non-directional wheel of a rolling object by means of a pushing device opposite to the tilting element and by means of an extendable arm on which the pushing device or the tilting element is mounted.

The invention also relates to a method for coupling a rolling object to an electric propulsion system as described above. The method comprises in particular the steps of:

b) extending the extendable arm, thereby enabling positioning of said wheel of the rolling object between the tilting element and the pushing means. For example, if the tilting element and the pushing means are positioned substantially at the height of the rotational axis of the wheel, the extendable arm may be extended such that the space between the tilting element and the pushing means is larger than the diameter of the wheel to be clamped. When the tilting element and/or the pushing means are located at a lower height than the rotation axis of the wheel (and therefore closer to the ground), the distance between the tilting element and the pushing means can be smaller than the diameter of the wheel to be gripped, but it is still necessary to achieve that the wheel of the rolling bodies is set between the tilting element and the pushing means,

c) moving the electric propulsion system so that the wheels of the rolling bodies are positioned between the tilting element and the pushing means, ready to be gripped and lifted,

d) the extendable arm is shortened to cause the pushing means or tilting element to contact the roller body's wheel,

e) the extendable arms continue to be shortened so that the pushing means drive the wheels of the rolling bodies into the tilting element, which at the same time lifts the wheels of the rolling bodies.

According to an advantageous embodiment of the invention, two wheels of the rolling bodies can advantageously be gripped and lifted, for example two non-oriented wheels of the rolling bodies, such as the rear wheels of a wheelchair. The propulsion system therefore advantageously comprises two combined and simultaneous gripping and lifting devices moving in lateral translation with respect to each other, each dedicated to a different wheel(s) of the rolling-bodies. Accordingly, a method for coupling a rolling object to an electric propulsion system may comprise the steps of:

b) at least one of the two combined and simultaneously gripping and lifting means is laterally moved with respect to the other combined and simultaneously gripping and lifting means,

c) the extendable arms of each combined and simultaneously gripping and lifting device are elongated so that the spacing between the tilting element and the pushing means allows the passage of the different (one) wheel of the rolling object. For example, when the pushing means and the tilting element are positioned at the height of the rotation axis of the rolling body, the space between the tilting element and the pushing means may be larger than the diameter of the wheel of the rolling body. If they are positioned at a lower height, closer to the ground, the space between the tilting element and the pushing means can be smaller than the diameter of the wheel of the rolling body between the tilting element and the pushing means. Step c) may be performed before, after or simultaneously with step b),

d) moving laterally at least one of the two combined and simultaneously gripping and lifting devices with respect to the other in a direction opposite to step b), until each wheel of the rolling bodies is positioned in a position between the pushing device and the tilting element,

e) the extendable arm is shortened so that each wheel of the rolling bodies is driven into each tilting element by means of the pushing means, which simultaneously lifts the wheel of the rolling bodies.

By way of non-limiting example, fig. 1 schematically illustrates an electric propulsion system 1 according to an embodiment of the present invention. Fig. 1 is a top view of an electric propulsion system 1. The electric propulsion system 1 comprises a chassis 2. Axis x corresponds to the longitudinal axis of chassis 2 and the main direction of displacement of propulsion system 1, while axis y corresponds to the transverse axis of chassis 2 (axis z, not shown, is vertical). The chassis 2 supports wheels 3 at one longitudinal end of the electric propulsion system 1 (alternatively, the chassis 2 may support two wheels 3), which are wheels driven by an electric motor (not shown). The wheel 3 is orientable about a vertical axis 8 with respect to the chassis 2. At the other longitudinal end of the electric propulsion system 1, the electric propulsion system comprises two wheels 4, which are wheels that are not driven by an electric motor. The two wheels 4 are eccentric wheels which can be oriented about a vertical axis 9. The electric propulsion system 1 further comprises a coupling device.

According to the shown embodiment the coupling device comprises two combined and simultaneously gripping and lifting devices. Each combined and simultaneous gripping and lifting device comprises a frame 23 and a tilting element 22, such as a tilter, connected to the frame 23 by a transverse axis pivot connection 21. Each combined and simultaneously gripping and lifting device further comprises a pushing device 20 connected to an arm 24 which can be extended in the longitudinal direction. Thus, the extendable arms 24 have a variable length in the longitudinal direction. One end of the extendable arm 24 is secured to the frame 23. The extendable arm 24 thus allows shortening or lengthening the longitudinal distance between the tilting element 22 and the pushing means 20, thereby positioning the wheel of the rolling object between these two parts, which wheel is then driven into the tilting element 22. The extendable arm 24 may particularly comprise a cylinder for controlling the extension or shortening of the extendable arm 24. The non-driven wheel 4 will be mounted by means of the vertical axis 9 at the longitudinal end of each extendable arm 24 opposite the end connected to the frame 23. Therefore, the distance between the non-driving wheel 4 and the chassis 2 may vary. Positioning the non-driven wheels 4 on the extendable arms 24 improves the load carrying capacity once the rolling objects are coupled to the electric propulsion system 1.

In order to ensure the distance and proximity of the frames 23 with respect to each other (and thus the transverse distance between the tilting elements and the transverse distance between the pushing means), the two frames 23 are connected by a sliding connection in the transverse direction 30. This function can be achieved, for example, by means of a (pneumatic) cylinder or a toothed rack. The coupling device is arranged in the x-direction between the traction wheel 3 and the orientable eccentric 4.

Furthermore, electric propulsion system 1 comprises a handlebar 6, for example in the form of a rod, equipped with a handle (not shown).

Furthermore, the electric propulsion system 1 may comprise a support platform 7 (e.g. for supporting a user).

As a non-limiting example, fig. 2 schematically shows a variant of fig. 1. Like reference numerals correspond to like elements and like operations, and therefore, will not be described in detail herein. Fig. 2 differs from fig. 1 in that the frame 23 is longitudinally adjustable on the chassis. In other words, the longitudinal position of the frame 23 along the chassis 2 can be changed. The frame 23 is movable in the direction RH. As schematically shown in the figure, three longitudinal positions P1, P2 and P3 are shown for each frame 23 on the chassis 2. These three positions P1, P2, P3 are represented by apertures in which pins can be set to lock the frame 23 in the desired longitudinal position. Alternatively, the longitudinal adjustment may be provided in a more precise manner by an actuator, such as a pneumatic cylinder.

By way of non-limiting example, fig. 3 schematically shows an electric propulsion system 1 according to a first variant embodiment of the invention. Fig. 3 is a side view of the propulsion system 1. The electric propulsion system 1 comprises a chassis 2. The axis x corresponds to the longitudinal axis of the chassis 2 and the main direction of displacement of the propulsion system, while the axis z corresponds to the vertical axis of the chassis 2 and the axis y (not shown) corresponds to the transverse axis. The chassis 2 supports a wheel 3, which is a wheel driven by a motor 10 by means of a drive 17, such as a belt or chain (alternatively, the motor 10 may be connected directly to the wheel 3). The wheel 3 is orientable about a vertical axis 8 with respect to the chassis 2. The motor 10 may be integral with the vertical axis pivot 8 of the motorized wheel 3. At the other end of the propulsion system, two extendable arms, indicated by horizontal double arrows, each support a wheel 4, the wheels 4 not being driven by a motor. The wheel 4 is eccentric with respect to the extendable arm and may be oriented about a vertical axis 9. The extendable arm may be elongated or shortened along the longitudinal direction x.

The electric propulsion system 1 further comprises a coupling device 5. The vertical movement of the coupling device 5 is illustrated by the vertical double arrow. This vertical movement of the coupling means, which is simultaneous and combined with the lateral movement of the coupling means 5, allows a combined and simultaneous gripping and lifting of the wheel of the rolling bodies, thus simultaneously producing a gripping and lifting of the wheel of the rolling bodies. A coupling device 5 is arranged in the x-direction between the traction wheel 3 and the orientable eccentric 4.

The coupling means comprise pushing means 20 positioned and fastened on the extendable arms.

Furthermore, electric propulsion system 1 comprises a handlebar 6, for example in the form of a rod, equipped with a handle (not shown) connected to undercarriage 2 by means of a joint 12.

Furthermore, the electric propulsion system 1 comprises a battery 11. A battery 11 is arranged on the chassis 2, close to the electric motor 10 and the motorized wheels 3.

By way of non-limiting example, fig. 4 schematically shows an electric propulsion system 1 according to a second variant embodiment of the invention. Fig. 4 is a side view of the electric propulsion system 1. The electric propulsion system 1 comprises a chassis 2. The axis x corresponds to the longitudinal axis of the chassis 2 and the main direction of displacement of the propulsion system, while the axis z corresponds to the vertical axis of the chassis 2. The chassis 2 supports a wheel 3, which is a wheel driven by a motor 10 by means of a drive 17, such as a belt or chain. The wheel 3 is orientable about a vertical axis 8 with respect to the chassis 2. The motor 10 may be integral with the vertical axis pivot 8 of the motorized wheel 3. At the other end of the propulsion system 1, two arms, indicated by horizontal double arrows, extendable in the longitudinal direction each support a wheel 4. The wheel 4 is not driven by a motor. The wheel 4 is eccentric with respect to the extendable arm and may be oriented about a vertical axis 9.

The electric propulsion system 1 further comprises a coupling device 5. The coupling means 5 comprise two combined and simultaneous gripping and lifting means on both sides of the chassis 2. The vertical movement of the combined and simultaneously gripping and lifting device is shown by the vertical double arrow. The vertical movement of the combined and simultaneously gripping and lifting device allows the combined and simultaneously gripping and lifting of the wheels of the rolling bodies. This vertical movement is driven by the lateral movement of the combined and simultaneously gripping and lifting device. A coupling device 5 is arranged in the x-direction between the traction wheel 3 and the orientable eccentric 4.

Each combined and simultaneously gripping and lifting means comprises pushing means 20 positioned and fastened on an extendable arm.

Furthermore, the electric propulsion system 1 comprises a handlebar 6, for example in the form of a rod, equipped with a grip (not shown) connected to the orientation axis 8 of the motorized wheel 3 by means of a joint 12.

Furthermore, the electric propulsion system 1 comprises a battery 11. The battery 11 is arranged in the vicinity of the non-motorized wheel 4.

By way of non-limiting example, fig. 5 schematically shows an electric propulsion system 1 coupled to a rolling object represented by a rectangle shown in dotted lines, according to an embodiment of the invention. Fig. 5 is a top view of the electric propulsion system 1 coupled to the rolling object. The embodiment of fig. 5 substantially corresponds to the embodiment of fig. 1 (the platform 7 of fig. 1 is not shown for reasons of chart readability). Those reference numerals that are the same as those of fig. 1 correspond to the same elements, and thus are not described in detail herein. The rolling bodies can be of any type, in particular wheelchairs, the electric propulsion system 1 being particularly suitable for gripping and lifting non-oriented wheels. The rolling body comprises two wheels 14, referred to herein as rear wheels, which may advantageously be non-oriented wheels; and two wheels 13, which are optionally referred to as front wheels. The electric propulsion system 1 comprises a chassis 2. Axis x corresponds to the longitudinal axis of chassis 2 and the main direction of displacement of propulsion system 1, while axis y corresponds to the transverse axis of chassis 2. The chassis 2 supports wheels 3, which are wheels driven by a motor (not shown). The wheel 3 is orientable about a vertical axis 8 with respect to the chassis 2. The other end of the electric propulsion system 1 is provided with two extendable arms 24 carrying two wheels 4 not driven by the electric motor, these wheels 4 being eccentric and orientable about the vertical axis 9. The electric propulsion system 1 further comprises a coupling device provided with two combined and simultaneously gripping and lifting devices, each close to a lateral end of the electric propulsion system 1. The combined and simultaneously gripping and lifting means each comprise a frame 23 connected to the chassis 2 by a transverse axis sliding connection 30. In fig. 5, the lateral sliding connection 30 is common to both frames 23. On each frame 23, a tilting element 22 is mounted on the transverse axis pivot connection 21. In addition, a pushing device 20 is secured to each extendable arm 24. The longitudinal movement of each extendable arm 24 thus drives the pushing device 20 towards the tilting element 22 (movement of the extendable arm 24 in direction-x), or conversely, in the opposite direction (movement of the extendable arm 24 in direction x).

As shown in fig. 5, the rear wheel 14 has been driven by the pushing device 20 towards the tilting element 22, causing the wheel 14 of the rolling body to be gripped and lifted.

Electric propulsion system 1 also comprises a handlebar 6, for example in the form of a rod, equipped with a handle (not shown) articulated with respect to chassis 2.

For the embodiment shown in fig. 5, the coupling means 5, the non-motorized wheel 4, the main part of the electric propulsion system 1 are arranged below the rolling bodies. In the longitudinal direction x of the undercarriage 2, only the motorized wheel 3 and the handlebar 6 can protrude from the rolling bodies 13.

By way of non-limiting example, fig. 6 schematically shows a first embodiment of a combined and simultaneously gripping and lifting device of a propulsion system according to the invention.

The propulsion system comprises a coupling device 5 with combined and simultaneous gripping and lifting means. This combined and simultaneous gripping and lifting device comprises a gripping element comprising a frame 108, which is a vertically immovable structure. A tilting element (e.g., a tilter) 100 is secured to the frame 108. The tilting element 100 is connected to the frame 108 by a transverse axis pivot connection 103, orthogonal to the plane of the cut, direction x representing the longitudinal direction and direction z representing the vertical direction. The tilting element 100 comprises two

portions

101 and 102 rigidly fixed to each other and forming a non-zero angle θ, thus forming a curved piece. The tilting of the tilting element 100 takes place by the weight of the tilting element itself alone or by the weight of the tilting element supporting the animal body. In other words, the tilting of the tilting element 100 is not controlled by the control means (e.g. the cylinder). The pivot connection 103 is advantageously positioned at the junction between the two

portions

101 and 102 forming the opening angle θ.

A pushing means connected to an arm (not shown) extendable in the longitudinal direction x is arranged opposite to the tilting element 100. The pushing means comprises a support 33 connected to the extendable arm. For example, it may be fastened to the extendable arm. The support 33 supports two

rollers

31 and 32 which can pivot about their

transverse axes

34 and 35, respectively, and are connected to the support 33. The diameter of the first roller 31 is smaller than the diameter of the second roller 32, and the height of the transverse axis 34 of the first roller 31 is lower than the height of the transverse axis 35 of the second roller 32. The first roller wheel 31 is thus designed to provide a first contact between the pushing device and the wheel 14 of the rolling body. Once wheel 14 begins to lift in tilting element 100, wheel 14 comes into contact with second roller 32. Since this second roller has a larger diameter and a higher height, it achieves an improved holding in place of the wheel 14 of the rolling bodies in the tilting element 100 during operation. In other words, the second roller 32 is a better obstacle than the first roller 31 for holding the rolling bodies in the electric propulsion system.

Fig. 6 shows the different steps relating to the approach, clamping and lifting of at least one wheel of the rolling bodies in five views a), b), c), d) and e).

In step a), the wheel 14 of the rolling body is not in contact with the tilting element 100 nor with the pushing means of the combined and simultaneously gripping and lifting device. It is in particular distanced from the portion 102 of the tilting element 100 and from the first roller 31 of the pushing device. The portion 102 is a short distance from the ground to facilitate gripping and lifting of the wheel.

The black arrows indicate the movement applied to the pushing means in the direction of the tilting element by means of extendable arms, not shown.

In step b), the pushing means are in contact with the wheel 14 of the rolling body. In fact, the first roller 31 is in contact with the wheel 14.

As the longitudinal displacement of the pushing means towards the tilting element 100 continues, the pushing means (first roller wheel 31) drives the wheel 14 of the roller body towards the tilting element.

In step c), the wheel 14 of the rolling body driven by the pushing means is in contact with the tilting element 100 at point a. Once contact between the tilting element 100 and the wheel 14 of the rolling body is achieved at point a, the tilting element 100 is tilted until a second contact between the wheel 14 of the rolling body and the tilting element 100 is achieved at point B, as shown in fig. d). The assembly consisting of the tilting element 100 and the wheel 14 of the rolling body can then be tilted, which at the same time allows the wheel 14 of the rolling body to be gripped and lifted. Continuation of the longitudinal movement of the extendable arm causes the tilting element 100 and the wheel 14 of the rolling body to tilt. The gap j1 which can be seen in fig. d) then occurs between the lower part of the wheel 14 of the rolling body and the ground, which is represented in the figures by the solid horizontal line. It is also noted that the tilting element 100 has turned slightly about its pivotal connection 103, the wheel being in contact with the wheel support portion 102 at contact point a and with the other portion 101 of the tilting element 100 at contact point B.

As the longitudinal displacement of the pushing device continues, the tilting element 100 rotates about its pivotal connection 103, since each wheel 14 of the rolling body bears against the tilting element. The combined and simultaneous gripping and lifting device continues to grip and lift the wheels 14 of the rolling bodies until the final position shown in figure e) is reached, in which the gap j2 between the lower part of each wheel 14 of the rolling bodies and the ground is maximum, j2 being greater than j 1. In this final position, each wheel 14 of the rolling body is fixed in the coupling device 5 and bears in the longitudinal direction against a first stop 120 on the frame 108. Furthermore, the holding portion 110 allows the tilting element 100 to be held in this position against the frame 108, which position is referred to as the raised position. This holding portion 110, which is also positioned on the frame 108, is arranged below the tilting element 100 in the raised position. The holding portion 110 allows to withstand the forces related to the weight of the rolling bodies on the combined and simultaneously gripping and lifting device, thereby achieving a limitation of the fatigue of the tilting element 100.

The holding part 110 and/or the first stop 120 are preferably made of a flexible material, such as rubber, in order to avoid static redundancy on the one hand and to adapt to different wheel diameters on the other hand.

It can also be noted that in the final position in figure e) the wheel 14 of the rolling body is in contact with the second roller 32, while the first roller 31 will not allow the wheel 14 to be held in the tilting element, because its diameter is too small and its position relative to the final position of the wheel 14 of the rolling body is too low.

Thus, the clamping and lifting of the wheel 14 of the rolling bodies is carried out in a combined and simultaneous manner by applying a single longitudinal translational movement (black arrow).

Fig. 6 shows a method and system in which the pushing means are driven in translation by extendable arms, but it is clear that the system may be reversed, in which case the tilting element may be driven by extendable arms, while the pushing means are fixed to the frame.

By way of non-limiting example, fig. 7 schematically shows another embodiment of a combined and simultaneously gripping and lifting device of a propulsion system according to the invention.

In this figure the propulsion system comprises a coupling device 5 with combined and simultaneous gripping and lifting means. This combined and simultaneous gripping and lifting device comprises a gripping element comprising a frame 108, which is a vertically immovable structure. The tilting element 100 is fastened to the frame 108 by means of a transverse axis pivot connection 103, orthogonal to the plane of the cut, the direction x representing the longitudinal direction and the direction z representing the vertical direction. The tilting element 100, for example a tilter, comprises two

portions

101 and 102 rigidly fixed to each other and forming a non-zero angle θ, thus forming a curved piece. The pivot connection 103 is advantageously positioned at the junction between the two

portions

101 and 102.

The angular gap limiting means 130 serves to limit the angular gap of the tilting element 100. It thus allows to define the distance between the bottom of the tilting element and the ground in the pre-rest position.

Furthermore, the combined and simultaneous gripping and lifting device comprises a pushing device fastened to an arm (not shown) that can be extended in the longitudinal direction x. The pushing means comprises in particular a support 33 connected to the extendable arm, such that a longitudinal displacement of the extendable arm is transmitted to the support 33. The roller 31 is mounted on a transverse axis pivot connection 34, which is itself mounted on a support 33.

Fig. 7 shows in five views a), b), c), d) and e) the different steps associated with the approach, clamping and lifting of at least one wheel of the rolling bodies.

In step a), the wheel 14 of the rolling object is not in contact with the tilting element 100 nor with the roller 31 of the pushing device of the combined and simultaneously gripping and lifting device. It is in particular distanced from the portion 102 of the tilting element 100 and from the first roller 31. In addition, the portion 102 is a short distance from the ground to facilitate gripping and lifting of the wheels of the rolling bodies.

The black arrows indicate the longitudinal movement imparted to the pushing device in the direction of the tilting element (in the-x direction) by means of extendable arms, not shown.

In step b), the roller 31 of the pushing device is in contact with the wheel 14 of the rolling body.

As the longitudinal displacement of the extendable arm continues, the pushing means then drives the wheel 14 of the roller body towards the tilting element.

In step c), the wheel 14 of the rolling body is in contact with the tilting element 100 at point a. The longitudinal movement of the extendable arm then causes the wheel to tilt about point a until it comes into contact with point B of the portion 101 of the tilting element 101. The gap j1 which can be seen in fig. c) then occurs between the lower part of the wheel 14 of the rolling body and the ground, which is represented in the figures by the solid horizontal line. It is also noted that each first tilting element 100 may have been slightly turned about its pivotal connection 103, the wheel being in contact with the wheel supporting portion 102 at contact point a and with the other portion 101 of each first tilting element 100 at contact point B. In other words, the portion 101 of the tilting element is no longer in contact with the angular gap limiting means 130.

The combined and simultaneously gripping and lifting device then continues to grip and lift the wheels 14 of the rolling bodies until reaching the final position shown in figure e), in which the gap j2 between the lower part of each wheel 14 of the rolling bodies and the ground is maximum, where j2 is greater than j 1. In this final position, each wheel 14 of the rolling body is fixed in the coupling device 5 and abuts against the first stop 31 in the longitudinal direction.

Fig. 7 shows a method and system in which the pushing means are driven in translation by extendable arms, but it is clear that the system may be reversed, in which case the tilting element may be driven by extendable arms, while the pushing means are fixed to the frame.

By way of non-limiting example, fig. 8 schematically shows another embodiment of a combined and simultaneously gripping and lifting device of a propulsion system according to the invention.

The propulsion system comprises a coupling device 5 with combined and simultaneous gripping and lifting means. This combined and simultaneous gripping and lifting device comprises a gripping element comprising a frame 108, which is a vertically immovable structure. A second tilting element 200 (e.g., a tilter) is secured to the frame 108. The second tilting element 200 is connected to the frame 108 by a transverse axis pivot connection 203, orthogonal to the plane of the cut, direction x representing the longitudinal direction and direction z representing the vertical direction. The tilting element 200 comprises two

portions

201 and 202 rigidly fixed to each other and forming a non-zero opening angle. The pivotal connection 203 is advantageously positioned at the junction between the two

portions

201 and 202.

The second tilting element 200 is itself connected to the first tilting element 100 by means of a substantially horizontal shaft 103 forming a pivotal connection between the first tilting element 100 and the second tilting element 200. The substantially horizontal axis 103 is oriented along a transverse direction (orthogonal to the plane of cut). The horizontal axis is thus parallel to the pivotal connection 203. The horizontal axis 103 is advantageously positioned at the junction between two rigidly connected

portions

101 and 102 forming a non-zero opening angle, the two

portions

101 and 102 constituting the tilting element 100, for example a tilter. The multiplicity of tilting elements allows to reduce the force required to initiate the gripping and lifting of the wheel 14 of the rolling bodies.

The pushing means are not shown in fig. 8. For example, it may correspond to the pushing means shown in fig. 6 or fig. 7. Only the black arrow shows the longitudinal displacement of the wheel 14 of the pushing means driving the roller body towards the tilting element.

Fig. 8 shows the different steps relating to the approach, clamping and lifting of at least one wheel of the rolling bodies in four figures a '), b'), c ') and d').

In step a'), the wheel 14 of the rolling body is not yet in contact with the tilting element 100. It is in particular at a distance from a portion 102 of the first tilting element 100, which portion 102 is at a greater distance from the ground in order to facilitate gripping and lifting of the wheels.

The black arrows indicate the displacement applied to the pushing means.

In step b'), the wheel 14 of the rolling body is in contact with the tilting element at point a. The tilting element 100 can then be pivoted until a second contact between the tilting element 100 and the wheel 14 of the rolling body is achieved at point B.

After contact is achieved at points a and B, longitudinal displacement of the pushing device towards the tilting element 100 causes the assembly consisting of the wheel 14 of the rolling body and the tilting element 100 to tilt, causing the wheel 14 of the rolling body to be gripped and lifted as shown in fig. c'). A gap j1 occurs between the lower part of the wheel 14 of the rolling body and the ground, which is indicated in the figures by a solid horizontal line.

As the longitudinal displacement of the pushing device continues, when each wheel 14 of the rolling bodies rests on each first tilting element 100, the first tilting element 100 is driven in rotation about its pivot adapter 103, each first tilting element 100 driving the second tilting element 200 in rotation about its pivot connection 203. A stop (not shown) may be provided between the wheel and the tilting element 200 or between the tilting element 100 and the tilting element 200 to allow the tilting element 200 to be driven in rotation. The combined and simultaneously gripping and lifting device then continues to grip and lift the wheels 14 of the rolling bodies until reaching the final position shown in figure d'), in which the gap j2 between the lower part of each wheel 14 of the rolling bodies and the ground is maximum, where j2 is greater than j 1. In this final position, each wheel 14 of the rolling body is fixed in the coupling device 5 and rests against a pushing device (e.g. a roller wheel) in the longitudinal direction.

Furthermore, the second angular gap limiting means 230 positioned on the frame 108 prevents an angular displacement of the portion 201 of the second tilting element 200 beyond the angular gap limiting means 230. In fig. a '), b ') and c '), the portion 201 of the second tilting element 200 is in contact with the angular gap limiting means 230, the angular gap limiting means 230 thus fulfilling its purpose by limiting the rotation of the second tilting element 200 about its pivotal connection 203. In fig. d'), the portion 201 of the second tilting element 200 is no longer in contact with the angular gap limiting device 230.

This configuration allows limiting the variation of the force for gripping and lifting the wheel of the rolling bodies immediately after the contact point a and until the wheel comes into contact with the point B.

Thus, the clamping and lifting of the wheel of the roll-fed body is performed in a combined and simultaneous manner by applying a single longitudinal translational movement (black arrow).

Fig. 8 shows a method and system in which the pushing means are driven in translation by extendable arms, but it is clear that the system may be reversed, in which case the tilting element may be driven by extendable arms, while the pushing means are fixed to the frame.

Figures 9a to 9g schematically show, by way of non-limiting example, the different steps of gripping and lifting two wheels of a rolling-object body according to a variant of the electric propulsion system of the invention, which comprises two devices that are combined and simultaneously gripping and lifting. The x-axis corresponds to the longitudinal axis and the y-axis corresponds to the transverse axis.

The propulsion system comprises a coupling device with two combined and simultaneously gripping and lifting devices. Each combined and simultaneous gripping and lifting device comprises a frame 23 and a tilting element 22, the tilting element 22 being connected to the frame 23 by a transverse axis pivot connection 21. The pushing means is fastened to an extendable arm 24 connected to the frame 23. Thus, the distance between the pushing means and the frame 23 can be varied by lengthening or shortening the extendable arms 24. The eccentric non-driving wheel 4, orientable about the vertical axis 9, is positioned at the longitudinal end of the extendable arm opposite to the longitudinal end of the extendable arm fastened to the frame 23.

The two frames 23 are in a transverse axis sliding connection 30, so that the two combined and simultaneously clamped and lifted devices are moved transversely away from each other. In other words, the lateral distance between the two combined and simultaneously clamped and lifted means can be varied by sliding one and/or the other of the combined and simultaneously clamped and lifted means along the lateral axis slide 30. This (or these) translations may be actuated, for example, by hydraulic, electric or pneumatic cylinders.

The pushing means comprise in particular a support secured to the extendable arm. The roller 31 is connected to the support by a transverse axis pivot connection 34.

Furthermore, an approach stop 40 is fastened to the frame 23, close to the lateral ends of the tilting element 22 of each combined and simultaneously clamped and lifted device. Alternatively, the proximity stop may be secured to a lateral end of the tilting element.

The approach stop 40 extends substantially in the longitudinal direction, in the direction of the pushing device opposite to the tilting element 22, and it is positioned on the outside of the electric propulsion system. Thus, when the combined and simultaneously clamped and lifted device moves in the transverse direction, the wheel 14 of the rolling body comes into contact with the proximity stop 40. Once contact is achieved, the lateral displacement of the combined and simultaneously clamped and lifted device may be stopped.

Fig. 9a shows an example of a situation in which the initial position of the combined and simultaneously clamped and lifted device does not allow the wheel 14 of the rolling object to be positioned between the roller wheel 31 of the pushing device and the tilting element 22.

Fig. 9b shows a first step in which the two combined and simultaneously gripping and lifting means are moved away from each other by means of the slide 30. This distance is indicated by the transverse double arrow in the figure. As shown, moving the two combined and simultaneously gripping and lifting devices away from each other allows the electric propulsion system to be driven forward in the direction of the rolling bodies, so that the combined and simultaneously gripping and lifting devices are each positioned on the lateral outer side of the rolling bodies.

The transverse displacement produced by the extension of the slide 30 drives the wheels 4 of the electric propulsion system towards the inside of the electric propulsion system. In fact, the wheel 4 is self-orienting, the lateral displacement of the slider 30 driving the wheel 4 in a lateral direction and in a direction opposite to the displacement of the slider 30.

Fig. 9c shows the relative positioning of the wheels 14 of the rolling bodies and the combined and simultaneously clamped and lifted device once the electric propulsion system has moved forward in the longitudinal direction as indicated by the horizontal double arrow.

In fig. 9d, the two combined and simultaneously gripping and lifting devices are moved closer to each other by the transverse axis slide 30 until each of the wheels 14 is in contact with the approach stop 40. Once contact is achieved, the lateral translation of the combined and simultaneously clamped and lifted device is stopped.

The transverse displacement produced by reducing the length of the slide 30 drives the wheels 4 of the electric propulsion system towards the outside of the electric propulsion system. In fact, the wheel 4 is self-orienting, the lateral displacement of the slider 30 driving the wheel 4 in a lateral direction and in a direction opposite to the displacement of the slider 30.

In fig. 9e, the extendable arm 24 is shortened. In practice, the extendable arm 24 performs a longitudinal translation F1 in the direction of the frame 23. Thus, the displacement of the extendable arm drives the pushing means, and in particular the drive roller 31.

This longitudinal displacement F1 provides contact between each wheel 14 and the roller wheel 31 of the pushing device. Once contact is achieved, the continuation of the longitudinal displacement F1 drives the wheel 14 of the roller body towards the tilting element 22. This displacement also drives the wheels 4 of the electric propulsion system in the longitudinal direction.

In fig. 9f, it can be seen that each wheel 14 is in contact with a tilting element 22.

As the longitudinal displacement F1 of the extendable arm 24 continues, the wheels 14 reach their final position in the tilting element, while remaining in contact with the roller 31 of the pushing device. These final positions are shown in fig. 9 g. The coupling of the rolling bodies to the electric propulsion system is then completed. The rolled bodies can then be easily transported by means of an electric propulsion system.

Reducing the length of the extendable arm 24 results in the wheels 4 of the electric propulsion system being oriented in the opposite longitudinal direction to the extendable arm 24, i.e. in the opposite direction to the displacement of the extendable arm 24.

As a non-limiting example, fig. 10 schematically illustrates a variation of the system illustrated in fig. 9a to 9 g. In this variant, the pushing means comprise two

guides

51a and 51b positioned on the two sides of the roller 31. According to a variant, these two

guides

51a and 51b can be positioned on each side of the tilting element. The x-axis corresponds to the longitudinal axis and the y-axis corresponds to the transverse axis.

The two

guides

51a and 51b extend substantially in the longitudinal direction in the direction of the frame 23. These two

guides

51a and 51b prevent the orientable wheel 14 of the rolling body from pivoting during the longitudinal displacement of the extendable arm towards the tilting element. In other words, the two

guides

51a and 51b hold the wheel 14 substantially in the longitudinal direction.

Furthermore, at least one of the two

guides

51a and 51b can be moved in the transverse direction Reg, so that the space between the two guides can be adapted to the width of the wheel 14 of the rolling body.

Thus, when the wheels 14 are orientable, their orientation can be maintained with good precision along the longitudinal direction.

In addition, in contrast to the system shown in fig. 9a to 9g, the pushing means comprise a second roller 32 connected to the support by a transverse axis pivot connection 35. The two

transverse axes

34 and 35 are therefore parallel to each other. The height of the transverse axis 35 of the second roller 32 above the ground is greater than the height of the transverse axis 34 of the first roller 31 above the ground. Further, the diameter of the second roller 32 may be larger than that of the first roller 31. This twin roller configuration provides greater adaptability of the system to the wheels 14 of different diameters of the rolling bodies, the second roller 32 provides a better obstacle, in particular to the operation of the assembly that remains coupled, the first roller 31 serving to initially push the wheels and to promote the start of contact and lifting of the wheels 14 of the rolling bodies in the tilting element 22.

By way of non-limiting example, fig. 11a and 11b schematically show an embodiment of a device for lifting a combined and simultaneously clamping and lifting device according to the invention.

In these figures, the combined and simultaneous gripping and lifting device includes a frame 108. The tilting element is constituted 2 by two

portions

102 and 10 rigidly fixed to each other and forming a non-zero opening angle, the tilting element being positioned on the frame 108. The tilting element pivots about a horizontal axis pivot connection 103 connected to the frame 108 so that the tilting element can rotate relative to the frame 108. The tilting element allows to simultaneously achieve clamping and lifting of the wheel of the roll-fed body. The pivot connection 103 is advantageously positioned at the junction between the two

portions

101 and 102.

Furthermore, the holding part 310 allows to support the tilting element when the holding part 310 supports the wheel of the supporting animal body, thereby improving the bearing of forces and limiting fatigue of the tilting element. According to a variant, the holding portion 310 may support the wheels of the animal.

Furthermore, the cam 145 is rigidly fastened to the tilting element. At the end of the cam 145 not fastened to the tilting element, a displacement in the longitudinal direction may be applied by means of, for example, a rod or a cylinder. This displacement is indicated by the double arrow. When the cam 145 moves in the direction of the frame 108, the cam 145 raises the tilting element. Then, the ground clearance increases. On the other hand, displacement of the cam 145 in the opposite direction to the frame 108 causes the tilting element to descend, very close to the ground, thus promoting gripping and lifting of the wheel of the rolling object. The displacement of the cam 145 can be advantageously associated with an actuator that simultaneously allows raising the tilting elements of two opposite, combined and simultaneously gripping and lifting devices.

The cam 145 may be driven, for example, by a pushing device which itself is driven by an extendable arm.

Alternatively or in combination, a counterweight system may be used to raise the tilting element.

Fig. 11a shows the tilting element in a rest position ready to grip and lift the wheel of a rolling object.

In fig. 11b, the rest position is indicated by a dashed line, and the raised position of the tilting element is indicated by a solid line. It can therefore be noted that the portion 112 of the support wheel which is initially in the lowest point is raised and is therefore at a higher level in the raised position than in the rest position.

Fig. 12 and 13 show the evolution of the force Fv exerted by the cylinder(s) during the stroke co (in the transverse direction) applied to the combined and simultaneously gripping and lifting device, the initial point of stroke co corresponding to the first contact between the wheel of the rolling body and the first tilting element. The stroke co occurs in the longitudinal direction of the propulsion system.

These figures also show the wheel height dp relative to the ground during the stroke co.

Curve Fv1 shows the evolution of the applied force, while curve dp1 shows the height of the wheel of the rolling body.

Fig. 12 and 13 show the evolution of the force Fv1 applied and the evolution of the height of the wheel of the rolling body for the two embodiments of the combined and simultaneous clamping and lifting device according to the invention.

Fig. 12 shows the case of a system according to the invention with a single tilting element, while fig. 13 shows the case of a system according to the invention with a tilting element and a device for limiting the angular play of the tilting element. The system in fig. 12 corresponds to the embodiment of fig. 6, and the system in fig. 13 corresponds to the embodiment of fig. 7.

These figures correspond to a rolling body with a gripping and lifting weight of about 400N, i.e. substantially 100N per wheel (for four-wheeled rolling bodies). It is noted that for both systems the height of the wheels is about 40mm, which height will provide sufficient ground clearance once the system is coupled to the rolling bodies.

Furthermore, it was observed that the addition of the angular gap limiting device between fig. 12 and 13 achieves a significant reduction in the maximum force required (from over 200N to less than 120N). In fig. 13, the maximum force corresponds to the instant the recliner loses contact with the angular gap limiting device. In fig. 12, the maximum force corresponds to the first contact of the wheel with the tilting element.

In fig. 13, the first portion is observed, where the force Fv1 decreases, then increases abruptly, and then decreases again. The time of this sudden increase corresponds to the time when the element loses contact with the angular gap limiting means, i.e. the time when the tilting element starts to tilt. The same type of effect can be obtained by replacing the angular gap limiting means with a second tilting element as shown in fig. 8.

The propulsion system of the invention is particularly suitable for different rolling bodies with different track widths and different wheel diameters. Thus, it provides a great variability of use. The propulsion system is particularly suitable for gripping and lifting non-directional wheels of rolling stock, for example, the rear wheels of wheelchairs.

Claims

1. A removable electric propulsion system (1) for a rolling object (13), the propulsion system (1) comprising a chassis (2) provided with at least one wheel (3) driven by an electric motor (10), at least one non-driven wheel (4) and at least one coupling device (5) for coupling the electric propulsion system (1) to the rolling bodies (13), characterized in that said coupling means (5) comprise at least one device for clamping and lifting in combination and simultaneously at least one wheel (14) of said rolling bodies (13), and said combined and simultaneously gripping and lifting means comprise a frame (23, 108), at least one arm (24) that can be extended in a longitudinal direction and is connected to said frame (23, 108), at least one tilting element (22, 100) and at least one pushing means (20); one of said tilting element (22, 100) and said pushing means (20) is connected to an extendable arm (24) and the other to a frame (23, 108); -said pushing means (20) being able to drive at least one wheel (14) of said rolling body (13) along said longitudinal direction (x) into said at least one tilting element (22, 100); the tilting element (22, 100) is tiltable about an axis substantially in a transverse direction (21, 103, 203).

2. The system according to claim 1, characterized in that said extendable arm (24) supports at least one of said at least one non-driven wheel (4).

3. The system according to any one of the preceding claims, characterized in that said combined and simultaneous gripping and lifting means comprise at least one means (230, 130) for limiting the angular clearance of at least one of said tilting elements (22, 100).

4. The system according to any one of the preceding claims, characterized in that an approach stop (40) is positioned on the frame (23, 108) or on the tilting element (22, 100).

5. The system according to any one of the preceding claims, wherein said pushing means (20) comprise a roller (31, 32) fastened to at least one transverse axis (34, 35) of said extendable arm (24) or of said frame (23, 108).

6. The system according to claim 5, characterized in that said pushing means (20) comprise a first transverse axis (34) and a second transverse axis (35) roller (31, 32) fastened to said extendable arm (24) or to said frame (23, 108), said first roller (31) being configured to contact the wheel (14) of said rolling body (13) before said second roller (32), the height of the axis of said first roller (31) being lower than the height of the axis of said second roller (32).

7. A system as in claim 6, wherein the diameter of the first roller (31) is smaller than the diameter of the second roller (32).

8. The system according to any one of the preceding claims, characterized in that the coupling device (5) is adjustable in a longitudinal position (P1, P2, P3) along the chassis.

9. The system according to any one of the preceding claims, wherein the pushing device (20) comprises two guides (51a, 51b) extending substantially in the longitudinal direction (x), the guides (51a, 51b) being configured to prevent the wheel (14) of the rolling body (13) from pivoting.

10. The system according to any of the preceding claims, characterized in that at least one of said tilting elements (22, 100) comprises means for adjusting the width of said tilting element (22, 100), said means for adjusting the width of said tilting element (22, 100) preferably being a mobile flange or a shim.

11. The system according to any one of the preceding claims, wherein the electric propulsion system (1) comprises two combined and simultaneous gripping and lifting devices, each dedicated to a wheel (14) of the rolling bodies (13), the two combined and simultaneous gripping and lifting devices being moved in lateral translation with respect to each other.

12. The system according to any one of the preceding claims, wherein the frame (23, 108) is connected to the chassis (2) by a sliding connection in a transverse direction (30), preferably by an actuator.

13. A system according to any one of the preceding claims, characterised in that said combined and simultaneously gripping and lifting means comprise a lifting device configured to ensure a ground clearance in the lifted position greater than a predetermined height, preferably said predetermined height ranges between 30mm and 50mm, more preferably it is in the vicinity of 40 mm.

14. The system of claim 13, wherein the raising means comprises at least one return spring and/or at least one counterweight and/or at least one driven rod.

15. The system according to any one of the preceding claims, wherein the stop (120) is positioned on the frame (23, 108) or on the extendable arm (24) to provide contact of the tilting element (22, 100) in the raised position.

16. A coupled assembly comprising a rolling body (13), preferably a rolling body (13) comprising at least one non-oriented wheel, and an electric propulsion system (1) according to any of the preceding claims, the rolling body (13) being coupled to the electric propulsion system (1) by the coupling means (5).

17. A method for coupling a rolling object (13) to an electric propulsion system (1) according to any one of claims 1 to 15, the method comprising the steps of:

a) at least one wheel (14) moving the electric propulsion system (1) so that it is close to the rolling bodies (13),

b) lengthening the extendable arm (24) so as to enable the positioning of said at least one wheel (14) of said rolling-body (13) between the tilting element (22, 100) and the pushing means (20),

c) moving the electric propulsion system (1) so that the at least one wheel (14) of the rolling bodies (13) is positioned between the tilting element (22, 100) and the pushing device (20),

d) shortening the extendable arm (24) so that the pushing means (20) or the tilting element (22, 100) contacts the at least one wheel of the rolling bodies,

e) -continuing to shorten said extendable arm (24) so that said pushing means (20) drives said at least one wheel (14) of said rolling body (13) into said tilting element (22, 100).

18. Method for coupling a rolling object (13) to an electric propulsion system (1) according to claim 17, characterised in that the electric propulsion system (1) comprises two combined and simultaneously gripping and lifting devices, the method comprising the steps of:

a) two wheels (14) moving the electric propulsion system (1) so that it is close to the rolling bodies (13),

c) -elongating the extendible arm (24) of each combined and simultaneously gripping and lifting device, so that the space between the tilting element (22, 100) and the pushing means (20) allows the passage of the wheel (14) of said rolling-body (13),

d) moving laterally, in the opposite direction to step b), at least one of the two combined and simultaneously gripping and lifting devices with respect to the other combined and simultaneously gripping and lifting device, until each wheel (14) of the rolling bodies (13) is positioned in a position between the pushing device (20) and the tilting element (22, 100),

e) -shortening said extendable arm (24) so as to drive each wheel (14) of said rolling bodies (13) into each of said tilting elements (22, 100) by means of said pushing means (20).